8-Chloro-imidazo[1,2-a]pyrazine

6863-73-6

2032-35-1

69214-33-1

GENERAL STEPS: Mix 48% aqueous hydrogen bromide solution (0.893 mL) with distilled water (9 mL) and add 2-bromo-1,1-diethoxyethane (5.98 mL, 38.5 mmol). It was heated and stirred under reflux conditions for 1 hour. After completion of the reaction, distilled water and ether were added to the reaction mixture for partitioning. The aqueous phase was extracted with ether, all organic phases were combined, dried with anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. The resulting residue was mixed with a solution of 3-chloropyrazin-2-amine (2.0 g, 15.4 mmol) in dimethoxyethane (22 mL) and 48% aqueous hydrogen bromide (0.3 mL) was added. It was heated and stirred under reflux conditions for 3 hours. At the end of the reaction, the solid product was collected by filtration and washed with ether to afford 8-chloroimidazo[1,2-a]pyrazine (2.07 g, 88% yield) as a black solid. Mass spectrum (ESI) m/z = 154 ([M + H]+).